Low-cost corrosion-resistant iron-based medium-entropy alloy and application thereof

Abstract

The invention discloses a low-cost corrosion-resistant iron-based medium-entropy alloy and application thereof, and aims to solve the technical problem that the current iron-based medium-entropy alloy is difficult to resist oxygen radical corrosion in an aerobic acid environment. The Cu element is reasonably added into the FeCrNiSiAl alloy, the yield strength and plasticity of the alloy can be improved, meanwhile, the corrosion rate of the alloy in an acid environment can be remarkably reduced, and the corrosion rate of the alloy is reduced by nearly 50 times. The method has important significance on application of the FeCrNiSiAl alloy in the aerobic acid environment.

Description

Technical Field

[0001] The present invention relates to the technical field of iron-based alloys, and in particular to a low-cost, corrosion-resistant iron-based medium-entropy alloy and its application. Background Art

[0002] High entropy alloys have become alloy materials with development potential due to their excellent properties such as high strength, high toughness, wear resistance and corrosion resistance, but their high cost has hindered their industrialization process. Iron-based medium-entropy alloys can effectively reduce costs due to their rich low-cost iron elements. At the same time, thanks to their TRIP effect at low temperatures, they can not only have good mechanical properties at room temperature, but also have excellent performance at low temperatures. At present, the development of iron-based medium-entropy alloys shows its great potential in many fields, but it also faces challenges such as alloy design (for example, how to screen suitable element combinations and how to design alloy compositions is still a difficult problem), the complexity of the corrosion process, and the difficulty in predicting performance trends. In addition, the huge composition and microstructure space of high-entropy alloys bring complexity to material design issues.

[0003] Researchers are also continuously improving the corrosion resistance of iron-based medium-entropy alloys, hoping to achieve or even surpass the corrosion resistance of traditional stainless steels such as 304 and 316. Ordinary stainless steel and iron-based medium-entropy alloys are difficult to resist the corrosion of aerobic radicals, such as sulfate radicals, in an aerobic acid environment. Therefore, developing an iron-based medium-entropy alloy that can balance mechanical properties and cost and has good acid corrosion resistance is of great significance for some industries that require acid-resistant materials, such as chemical, electric power, and petroleum industries.

[0004] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] In view of at least one of the above technical problems, the present disclosure provides a low-cost corrosion-resistant iron-based medium-entropy alloy and its application, aiming to solve the technical problem that the current iron-based medium-entropy alloy is difficult to resist aerobic root corrosion in an aerobic acid environment.

[0006] According to one aspect of the present disclosure, a low-cost corrosion-resistant iron-based medium-entropy alloy is provided, wherein the alloy chemical formula is Fe 67-x Cu x Cr 15-17 Ni 9-11 Si 4-6 Al 1-3 , where 0 <x≤4。

[0007] In some embodiments of the present disclosure, the alloy chemical expression is Fe 67-x Cu x Cr 15-17 Ni 9-11 Si 4-6 Al 1-3 , where 2≤x≤4.

[0008] In some embodiments of the present disclosure, the alloy chemical expression is Fe 67-x Cu x Cr 16 Ni 10 Si5Al2.

[0009] In some embodiments of the present disclosure, the alloy chemical expression is Fe 65 Cu2Cr 16 Ni 10 Si5Al2.

[0010] In some embodiments of the present disclosure, the alloy chemical expression is Fe 63 Cu4Cr 16 Ni 10 Si5Al2.

[0011] According to two aspects of the present disclosure, the low-cost corrosion-resistant iron-based medium-entropy alloy is applied in an aerobic acidic environment.

[0012] According to three aspects of the present disclosure, the low-cost corrosion-resistant iron-based medium-entropy alloy is applied in the preparation of corrosion-resistant / aerobic and acid-resistant products.

[0013] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages: Adding an appropriate amount of Cu element to the iron-based medium entropy alloy can have a significant effect on its microstructure and performance: it can not only improve the yield strength and plasticity of the alloy and reduce the cost of alloy raw materials, but also significantly reduce the corrosion rate of the alloy in an acidic environment (reduced by nearly 50 times), which has important application value for industries such as chemical, electric power and petroleum that require acid-resistant materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 In the embodiment of this application, Fe 67-x Cu x Cr 16 Ni 10 Tensile stress-strain curves and strain hardening rate curves of Si5Al2 (x=0, 2, 4) alloys; (a) and (b) are the tensile stress-strain curves and strain hardening rate curves at 298 K; (c) and (d) are the tensile stress-strain curves and strain hardening rate curves at 77 K.

[0015] Figure 2 In the embodiment of this application, Fe 67-x Cu x Cr 16 Ni 10 Corrosion of Si5Al2 alloy in 2 M H2SO4 solution; (a) is weight loss; (b) is corrosion rate. DETAILED DESCRIPTION

[0016] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0017] Unless otherwise specified, the instruments and equipment involved in the following embodiments are all conventional instruments and equipment; the metal raw materials involved are all commercially available conventional metal raw materials unless otherwise specified; the processing and manufacturing methods and testing methods involved are all conventional methods unless otherwise specified.

[0018] Embodiment 1 In this example, a low-cost, corrosion-resistant iron-based medium-entropy alloy is prepared. The specific steps are as follows: (1) Using elements with a purity greater than 99.9wt% as raw materials, arc melting is used in an Ar atmosphere to prepare a material with a nominal composition of Fe 67-x Cu x Cr 15-17 Ni 9-11 Si 4-6 Al 1-3 All the alloy ingots were remelted at least 5 times under electromagnetic stirring to ensure uniform composition.

[0019] (2) The molten alloy is then cast into a 10×10×40 mm 3 copper mold to obtain a cast alloy ingot.

[0020] (3) The cast alloy is subjected to 85% multi-pass rolling to obtain an alloy plate, and the thickness of the plate after rolling is 1.5 mm.

[0021] (4) The alloy plate is annealed at 800° C. for 10 min and then immediately water-cooled.

[0022] Embodiment 2 According to the composition of Fe 65 Cu2Cr 16 Ni 10 The composition of Si5Al2 is prepared according to the alloy preparation method described in Example 1.

[0023] Embodiment 3 According to the composition of Fe 63 Cu4Cr 16 Ni 10 The composition of Si5Al2 is prepared according to the alloy preparation method described in Example 1.

[0024] Embodiment 4 According to the composition of Fe 67 Cr 16 Ni 10 The composition of Si5Al2 is prepared according to the alloy preparation method described in Example 1.

[0025] Embodiment 5 The mechanical properties of the iron-based medium entropy alloys (Cu content of 0, 2%, and 4%, respectively) prepared in the above-mentioned Examples 2 to 4 were tested at 298 K and 77 K, and the results showed that ( Figure 1 As shown in Figure 2, the addition of Cu improves the yield strength and plasticity of the alloy, but excessive Cu will reduce the tensile strength of the alloy.

[0026] Embodiment 6 In this example, the corrosion resistance of the iron-based medium entropy alloys (Cu content of 2% and 4% respectively) prepared in the above-mentioned Examples 2 to 3 was tested, and their weight loss and corrosion rate in H2SO4 solution were tested, and their corrosion resistance was compared with that of Cu0 alloy and 304 stainless steel. The results are as follows: Figure 2 As shown, the results show that compared with Cu0 alloy and 304 stainless steel, the two Cu-containing alloys (Cu content is 2% and 4%, respectively) have lower corrosion rates, and their corrosion rates are reduced by nearly 50 times.

[0027] Although some preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0028] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the inventive concept. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A low-cost, corrosion-resistant iron-based medium-entropy alloy, characterized in that: In terms of atomic percentage, the alloy chemical formula is Fe 67-x Cu x Cr 15-17 Ni 9-11 Si 4-6 Al 1-3 , where 0 <x≤4。 2. The low-cost corrosion-resistant iron-based medium-entropy alloy according to claim 1, characterized in that: Its alloy chemical formula is Fe 67-x Cu x Cr 15-17 Ni 9-11 Si 4-6 Al 1-3 , where 2≤x≤4.

3. The low-cost corrosion-resistant iron-based medium-entropy alloy according to claim 1, characterized in that: Its alloy chemical formula is Fe 67-x Cu x Cr 16 Ni 10 Si5Al2.

4. The low-cost corrosion-resistant iron-based medium-entropy alloy according to claim 3, characterized in that: Its alloy chemical formula is Fe 65 Cu2Cr 16 Ni 10 Si5Al2.

5. The low-cost corrosion-resistant iron-based medium-entropy alloy according to claim 3, characterized in that: Its alloy chemical formula is Fe 63 Cu4Cr 16 Ni 10 Si5Al2.

6. Use of the low-cost, corrosion-resistant iron-based medium-entropy alloy according to any one of claims 1 to 5 in an aerobic acid environment.

7. Use of the low-cost corrosion-resistant iron-based medium-entropy alloy according to any one of claims 1 to 5 in the preparation of corrosion-resistant / aerobic and acid-resistant products.

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